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Childhood Obesity Prevention Programs: Comparative Effectiveness Presented by Youfa Wang, MD, PhD, MS Professor and Chair Department of Epidemiology and Environmental Health School of Public Health and Health Professions University at Buffalo, the State University of New York (SUNY)

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Childhood Obesity Prevention Programs:

Comparative Effectiveness

Presented by Youfa Wang, MD, PhD, MS

Professor and Chair

Department of Epidemiology and Environmental Health

School of Public Health and Health Professions

University at Buffalo, the State University of New York (SUNY)

Outline of What to Expect

• Definitions, incidence, and prevalence of childhood obesity

• Grading the strength of a body of evidence

• Clinical questions addressed

• What was found

• What was learned about interventions to prevent childhood obesity

• How to use these findings

2

AHRQ Comparative Effectiveness Review

Process

3

Topic Nomination

Peer Review Public

Comment

Systematic Review

Meta Analysis

Expert Input

Final AHRQ report, Clinician Summaries, and Consumer

Research Summaries

Introduction

4

http://www.effectivehealthcare.ahrq.gov

Learning Objectives

• Identify types of obesity prevention programs.

• Discuss the evidence on the effectiveness and

safety of prevention programs.

• Identify limitations in the current evidence base

related to interventions addressing childhood

obesity.

• Summarize future research directions such as

additional studies, study design, and analyses.

5

6

What is

obesity in

children? How

prevalent is

obesity in

children?

What are the

consequences?

Prevalence of Childhood Obesity

7

Prevalence of Childhood Obesity

0

2

4

6

8

10

12

14

16

18

20

2 – 5 years 6 – 11 years 12 – 19 years

Pro

po

rtio

n o

bese

Age of Children

Prevalence in the US by age: 1976-1980 to 2009-2010

1976 –1980

2009 – 2010

8

Health Consequences of Childhood

Obesity

9

Obese children

Adverse health conditions

Cardiovascular outcomes

Psychosocial outcomes

Eating disorders

Depression Low

self-esteem

Metabolic outcomes

Medical Complications of Obesity

10

Biological Basis for Obesity

11

Individual/Biological

Susceptibility

Dietary & Physical Activity

Patterns

Body Fat Stores

Energy Regulation

In Out

Factors Affecting Childhood

Obesity

12

Individual examples

• Genetics

• Nutrition knowledge

• Nutrition attitude

• Body weight image

Home examples

• Parenting

• Home diet

• Parental weight status

School examples

• Nutrition service

• Curriculum

• Annual BMI

Community examples

• Sidewalks

• Parks

• Safety from traffic

• Crime rate

Regional and National examples

• Price of food

• Food assistance programs

Defining Obesity and Overweight

13

• Different classifications

• Obesity in children:

► Medical condition in which excess body fat may have

adverse effect on health.

► ≥ age-sex-specific 95th percentile body mass index

(BMI).

• Overweight in children:

► ≥ age-sex-specific 85th percentile BMI, but < 95th

percentile.

Prevention vs Treatment

Prevention

• AKA “intervention”

• Goal: Prevent children from becoming overweight or obese

• May help overweight or obese children lose or stabilize weight

• Focus of this presentation

Treatment

• AKA “weight loss” or

“weight management”

• Goal: Weight loss among

pediatric patients.

• See AHRQ report Effectiveness of Weight

Management Interventions in

Children: a Targeted Systematic

Review for the USPSTF

14

Analytic Framework: Evaluation of

Childhood Obesity Interventions

15

Obesity-Related Clinical

Outcomes

Cardiovascular outcomes

Metabolic outcomes

Psychosocial outcomes

Settings

KQ1 – School

KQ2 – Home

KQ3 – Primary care

KQ 4 – Child care

KQ 5 – Community-level

KQ6 – Consumer health

informatics

KQ7 – Multi-setting

Adverse Effects of Intervention

Burden of intervention

Eating disorders

Psychosocial outcomes

Impact on growth and development

Injury

Cost

Other adverse events

All children age

2-18 years

Primary Outcomes

Change in overweight and obese status

Prevalence of overweight and obese

BMI

Other adiposity measures

Intermediate Outcomes

Nutrition knowledge, attitudes, beliefs

Food purchasing behaviors

Dietary intake

Food access

Physical activity

Sedentary behavior

Scope of the Review

Population Children 2-18 years old, regardless of BMI

Interventions a) Diet, physical activity, or combination of diet and physical activity

b) Setting of intervention

Comparators No intervention, usual care, or other intervention

Outcomes

a) Primary: Weight-related outcomes (e.g., BMI, obesity or

overweight rates)

b) Intermediate: Dietary intake (e.g., fruits and vegetables, sugar-

sweetened beverages), physical activity, sedentary activity

c) Adverse effects: Eating disorders, psychosocial outcomes, impact

on growth and development, injury, cost

d) Obesity-related clinical outcomes: Cardiovascular and metabolic

outcomes (e.g., blood pressure, blood lipids, blood glucose)

Timing a) ≥ 6 months for school-based interventions

b) ≥ 1 year for any other interventions

Settings School, home, primary care clinic, childcare, community,

environmental-level interventions, or any combination of settings

16

Literature Search, Data Collection,

and Analysis

• Data sources: ► MEDLINE®, Embase®, PsycInfo®, CINAHL®,

Clinicaltrials.gov, and the Cochrane Library through August 11, 2012.

• Study inclusion criteria ► Randomized controlled trials, quasi-experimental studies,

or natural experiments conducted in high-income countries.

• Study screening & data extraction: ► Two reviewers independently reviewed each article for

eligibility.

► For each study, one reviewer extracted the data and a second reviewer verified the accuracy.

• Meta-analysis

17

Key Questions

18

KQ 1 What is the comparative effectiveness of school-based

interventions for the prevention of obesity or overweight in children?

KQ 2 What is the comparative effectiveness of home-based interventions

for the prevention of obesity or overweight in children?

KQ 3 What is the comparative effectiveness of primary care–based

interventions for the prevention of obesity or overweight in children?

KQ 4 What is the comparative effectiveness of childcare setting–based

interventions for the prevention of obesity or overweight in children?

KQ 5 What is the comparative effectiveness of community-based or

environmental-level interventions for the prevention of obesity or

overweight in children?

KQ 6 What is the comparative effectiveness of consumer health

informatics applications for the prevention of obesity or overweight

in children?

KQ 7 What is the comparative effectiveness of multi-setting interventions

for the prevention of obesity or overweight in children?

Studies Addressing the Key

Questions

19

104 studies 6 studies 1 study

4 studies 9 studies 0 studies

Studies in multi-settings were presented under other KQs.

Strength of the Evidence

• Further research is very unlikely to change the confidence in the estimate of effect. High

• Further research may change the confidence in the estimate of effect and may change the estimate.

Moderate

• Further research is likely to change the confidence in the estimate of effect and is likely to change the estimate.

Low

• Evidence either is unavailable or does not permit estimation of an effect. Insufficient

20

What are school-based obesity prevention

interventions?

21

School-Based Interventions

• School as primary setting:

► Change in quantity of food

► Change in nutritional quality of food

► Increased physical activity

► Promotion of walk-to-school

► Combination of the above with home or community

interventions

22

School-Based Interventions

• Dietary interventions:

► Decrease in BMI or BMI Z-score

measures

Strength of Evidence: Moderate

• Physical activity interventions:

► Impact on BMI, waist

circumference (girls), skinfold

thickness, percentage body fat

Strength of Evidence: Moderate

23

School-Based Interventions

• Diet and physical activity

combined intervention and

weight-related outcomes:

► Reduced BMI, BMI Z-score,

prevalence of obesity and

overweight, percentage of

body fat, waist circumference,

and skinfold thickness

Strength of Evidence: Insufficient

24

School-Based Interventions: Change in BMI

Meta-Analysis: Change in BMI between Control and Combined Diet and Physical Activity Groups in School-Only Settings

School-Based + Home Components

• Dietary interventions:

► Effect on preventing obesity

unknown

Strength of Evidence: Insufficient

• Physical activity interventions:

► Improvement in BMI, waist

circumference, and skinfold

thickness

Strength of Evidence: High

26

School-Based + Home Components

• Diet and physical activity

combined interventions:

► Improvement in BMI, BMI

percentile, prevalence of

overweight or obesity

Strength of Evidence: Moderate

27

School-Based + Home

Components: Change in BMI

28

Meta-Analysis: Change in BMI between Control and Combined Diet

and Physical Activity Interventions in a School Setting with a Home

Component

School-Based Intervention + Home

+ Community Components

• Combination diet and physical activity

interventions:

► Improvement in weight outcomes

Strength of Evidence: High

• Physical activity interventions:

► Effect on preventing obesity unknown

Strength of Evidence: Insufficient

29

School-Based Intervention +

Community Component

• Dietary interventions:

► Improved BMI and prevalence of overweight and obesity

Strength of Evidence: Insufficient

• Physical activity interventions:

► No difference in weight-related outcomes

Strength of Evidence: Insufficient

• Combination diet and physical activity interventions:

► Nonsignificant improvements in weight outcomes

Strength of Evidence: Moderate

30

School-Based Intervention +

Consumer Health Informatics

31

Insufficient

Evidence

School-Based + Consumer Health

Informatics + Home Components

32

Insufficient

Evidence

What are home-based obesity prevention

interventions?

33

Home-Based Interventions

• Dietary interventions:

► No difference in BMI, fat mass, or weight

Strength of Evidence: Insufficient

• Combination diet and physical activity

interventions:

► No difference in weight outcomes

Strength of Evidence: Low

34

Home-Based + School +

Community Component

35

Insufficient

Evidence

Home-Based + Primary Care +

Consumer Health Informatics

36

Insufficient

Evidence

What are primary care–based obesity

prevention interventions? 37

Primary Care–Based Interventions

38

Insufficient

Evidence

What are childcare center obesity

prevention interventions? 39

Childcare Center Interventions

• Physical activity interventions:

► May improve BMI and percent body fat

Strength of Evidence: Insufficient

• Combination diet and physical activity

interventions:

► No difference in weight outcomes

Strength of Evidence: Low

40

What are community-based or

environmental-level obesity prevention

interventions?

41

Community-Based or

Environmental-Level Interventions

• Combination of diet and physical activity interventions: ► Community + school involvement resulted in a

beneficial effect on preventing obesity

Strength of Evidence: Moderate

• Diet, physical activity, or combination of interventions: ► Community level alone or other settings – ability to

prevent obesity unknown

Strength of Evidence: Insufficient

42

What are consumer health informatics

applications for the prevention of obesity?

43

Consumer Health Informatics

Applications

44

Insufficient

Evidence

Insufficient

Evidence

Harms of Interventions

45

Conclusions What did we learn?

46

Conclusions & Discussion

• School-based interventions:

► Moderate evidence of effectiveness

• School-based physical activity with family

component or combined interventions in school with

home and community components:

► Most evidence for effectiveness

• Interventions conducted as environmental strategies,

consumer health informatics strategies, or testing

policies:

► Lack of evidence to determine impact on preventing obesity

47

Summary of Key Evidence

Setting Intervention Measure Result Strength of Evidence

School-Based Diet BMI BMI Z-score

Improved Moderate

School-Based Physical activity

BMI Waist circumference (girls) Skinfold thickness % body fat

Improved Moderate

School-Based + Home

Physical activity BMI Waist circumference Skinfold thickness

Improved High

School-Based + Home

Diet + physical activity

BMI BMI percentile Prevalence of obesity or overweight

Improved Moderate

School-Based + Community

Diet + physical activity

BMI BMI Z-score

Improved Moderate

School-Based + Home + Community

Diet + physical activity

Weight outcomes Improved High

48

Limitations of the Evidence Base

• Lack of studies in clinical settings

• Limited evidence testing environmental-based

or policy interventions

• Insufficient evidence on the effect of consumer

health informatics

49

Gaps in the Evidence

• Need for greater understanding of contextual

factors associated with implementation

► Allow decision makers a better idea of applicability of

any given intervention

• Need for subgroup analyses by:

► Sex, age, race/ethnicity, socioeconomic status

• Need for additional evaluations of adolescents

► Obesity among adolescents more predictive of obesity

during adulthood

50

Applicability of the Results

• Children in high-income countries ► May not be applicable to children in middle- and low-

income countries

• Studies with subgroup analysis ► Applicability to very young children and select

racial/ethnic groups unknown

• Age of studies ► Older studies may not be as effective in current

populations

• Setting of studies ► Focus on RCTs may understate interventions in non-

school settings

51

What should I discuss with patients and their

caregivers? 52

What to Discuss with Patients

Concerns about childhood obesity and the

patient’s welfare

Patient’s BMI and how to diagnose overweight

and obesity in children

Factors contributing to overweight/obesity in

children:

Less physical activity

More sedentary/screen time

High calories, too much unhealthy food

Inappropriate use of food rewards

53

What to Discuss with Patients

Appropriate food serving size

Monitoring total daily caloric intake

What can be done at home

Health consequences of obesity in children

Effectiveness of obesity prevention interventions

Community or school obesity prevention

programs

What to do if healthy food or safe physical

activity locations are not accessible

54

Patient & Caregiver Information

55 Available at: http://effectivehealthcare.ahrq.gov

CONTINUING EDUCATION

CREDIT

56

Continuing Education Credit

• To obtain credit:

► Complete the online evaluation.

► Pass the posttest with a grade of 80% or higher.

If you have any problems receiving certification, please

contact:

Postgraduate Institute for Medicine

304 Inverness Way South, Suite 100

Englewood, Colorado 80112

Phone: (303) 799-1930

Fax: (303) 858-8848

Email: [email protected]

57

Acknowledgements

• Research team: Youfa Wang (PI), Yang Wu

(Coordinator), Jodi Segal (Task Leader), Li Cai,

Renee F. Wilson (Project Manager), Christine

Weston, Oluwakemi Fawole, Sara Bleich,

Lawrence J. Cheskin, Nakiya N. Showell,

Brandyn Lau, Dorothy T. Chiu, Allen Zhang

• Reviewers and experts who contributed to the

project

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